Smokey ink sort of has a heavy grit suspended in it. Use in a 3:1 or 2:1 water mix to get it to flow and dirty up all the edges and corners on your model. Apply a pure dab of it and spread it around thin for a more pronounced effect. Do not wet-blend with other colors. You'll get unpredictable results.

On the wing, I had it laying flat and gravity pulled the water outward along the panel seams and the wing edge. I figured the grit pattern would be outward. Cleaned the brush and touched it gently in spots along the wing panel to make various patterns. It's really fun to experiment with. It also makes great weathering on Gundam kits and works amazing on any tank model that uses Olive Green or Desert Yellow

Nothing in a while, but I did these two guys a couple weeks ago for a funsies no-prizes painting club. The theme was Central Asia in the 20's & 30's (referred to among wargamers as "Back of Beyond" wargaming, usually Russian civil war games).

The first one turned out, purely accidentally, to be a timely tribute.